<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - XWayland crashes during startup if output data is received" href="https://bugs.freedesktop.org/show_bug.cgi?id=95337#c4">Comment # 4</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - XWayland crashes during startup if output data is received" href="https://bugs.freedesktop.org/show_bug.cgi?id=95337">bug 95337</a> from <a class="email" href="mailto:fourdan@xfce.org" title="Olivier Fourdan <fourdan@xfce.org>"> Olivier Fourdan</a> <pre>(In reply to Jonas Ådahl from <a href="show_bug.cgi?id=95337#c2">comment #2</a>) > [...] > I think that if we don't roundtrip here, we might end up in a situation > where various places expects to be able to know things about wl_seat's etc, > that'd now start to crash if we loose the race against the wl_seat global > being discovered. I don't experience any crash with this patch applied, neither with mutter which spawns Xwayland at startup as it (still) relies on X, i.e. very early, nor with weston which spawns it when needed (ie with all outputs and seats set-up). > AFAICS InitInput() is done after InitOutput() which is where xwl_screen_init > and the first roundtrips are done. You're right, of course, but the problem is not much xwl_screen_init() but the X ConnectionInfo (as reported in <a href="show_bug.cgi?id=95337#c0">comment #0</a>) that gets initialized after InitInput is called in dix. It goes like this: xwl_screen_init() InitInput() ConnectionInfo initialized So if the roundtrip in InitInput() trigger something that needs to use the X connection (as with RR in the backtrace), it will crash. Meanwhile, ajax picked up the patch from the ML and pushed it, so it's landed in master (I did send the patch to the devel ML in parallel as this is where patches get discussed for xorg rather than bugzilla). But I am not convinced this patch would cause more bad that good, initializing xwl_screen->expecting_event to 0 twice at two different places doesn't sound right and doing the rountrip before X connection is likely to cause breakage as well, as seen in <a href="show_bug.cgi?id=95337#c0">comment #0</a>. Let's keep that bug opened and see if we get some more feedback (either here or on the xorg-devel ML), meanwhile please test master with different compositors and use cases and let's see if this a real problem. (In reply to Pekka Paalanen from <a href="show_bug.cgi?id=95337#c3">comment #3</a>) > Mind, wl_seats can come and go dynamically, and it is not guaranteed to have > at least one at all times. So, working without any seat would sound like a > good idea to me. > > The same goes for outputs, and will likely be testable on Weston once > Armin's GSoC project is near finishing. Yes, probably, but I reckon outputs are a different issue than this particular crash.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>